chuckdubs
Posts: 5
Joined: Wed Aug 15, 2018 4:10 pm

Raspi not detecting I2C component

Mon Aug 27, 2018 6:56 pm

I purchased a few air pressure sensors that communicate via i2c and am not having luck with raspi detecting them. Running raspbien stretch on a raspberry pi zero W

Here is device drawing:
Image

The device is listed as being able to take supply voltage of 3.3v or 5v.

Here's what I've done:
1) Turned on I2C in raspi-config and reboot
2) Verified physical pins 3 and 5 are set to 'ALT0' with 'gpio readall' command
3) Connected following pins: rpi gnd to component pin 1, rpi 3.3v to pin 2, rpi SDA to pin 3, and rpi SCL to pin 4
4) Check for device using 'gpio i2cd' and am getting all dashes

Here are images of how things are connected:
From the back of device:
Image

from top:
Image

gpios:
Image

I've never used i2c before, is there some way I can troubleshoot why these devices aren't being detected?

DirkS
Posts: 10371
Joined: Tue Jun 19, 2012 9:46 pm
Location: Essex, UK

Re: Raspi not detecting I2C component

Mon Aug 27, 2018 7:46 pm

To me it looks as if you're using 5V instead of 3V3.
You wired it to pin 4 instead of pin 3
https://pinout.xyz/pinout/pin4_5v_power

chuckdubs
Posts: 5
Joined: Wed Aug 15, 2018 4:10 pm

Re: Raspi not detecting I2C component

Mon Aug 27, 2018 9:04 pm

Thank you, that was the issue.

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